It might work, unless someone is stealing your Jeep at night, and then there's no deterant. I gotta search, but I've get a system of a hidden magnetic reed switch and a few relays. To start my Jeep I need to pass a magnet over the hidden switch (which can be anywhere) and then it'll start. Otherwise there's no ignition, but it'll crank, so it'll make a lot of noise and attract attention.

__________________
"If stupidity got us into this mess, why can't it get us out?" -Will Rogers

Man, if you wanted to go that route, the possibilities are endless. You could set it up to where it will only start if the left blinker is on while pushing the clutch while running your winch and the radio has to be set to 1600 AM. Just kidding, that is a pretty good idea though.

My theft detterent is pretty simple.. I just make it a point to ONLY drive vehicles that are SO ugly, and beat up, that nobody in there right mind would want to steal it. That idea works GREAT for me! I'm just about to hit 30, and haven't even had a stereo stolen once. The clostest I've had was somebody trying to steal my toolbox from next to my car in the middle of the night. Well, them seeing me coming with my baseball bat got them to stop really fast..

Oh Well, that's just my idea..

TheJunkMan2005

__________________1988 Wrangler 89000 miles, no rust, no rot, all nice and pretty.. Runs down the highway really nice too.. This is great fun.

Instead of going through all that trouble, why don't you just hide a switch going to your coil wire or to the starter solenoid.
I beat if you install a switch that looks like your fan switch no one would know the difference. Drill a hole above your headlight switch.

I installed a battery kill switch. I ran a bypass wire for the radio (clock). So far I don't know if it works as a deterent. No one has tried to borrow my Jeep without permission, but it does work!

Find a "closed when energized" relay and run the parking light circuit through it and attach the ignition wire.

Fint 2 "open when energized" relays and put one on the headlight circuit and one on the brake light circuit.

Pass the ignition through both of these in such a way that the only way to start the Jeep would be to pull the parking lights on and push the brak pedal while starting.

Gzus... You're creating a nightmarish no-crank troubleshoot for yourself, and you just know it's going to leave you stranded in the 7-11 parking lot at midnight on a Wednesday... That or at the Gas Station just when a bunch of ppl were going to say "nice jeep"

Some things that immediately strike me as complicated with your idea is that you really only have 2 condition wires that stand in between the Battery and the Starter Motor on the solenoid, and of those, you only have one that is typically OPEN during normal vehicle operation (Ignition BLUE). Soooo... Either one of your conditions would have to be put on ignition red, meaning one of the would have to be CLOSED any time the engine was running, or you want to put 3 conditions on one wire? Hmmm... I'm sure it can probably be done, but I can't fathom a schematic off the top of the noggin... research required....

Also, most SPDT Relays can be made in to a Normally Open or Normally Closed relay regardless of their actual manufacture because either pin 87 or pin 87a is going to be one of those conditions at all times, depending on the state of coil charge.

Ok. So I'm thinking that this could be done with 2 relays, not 3. If the stated purpose is accurate "Pass the ignition through both of these in such a way that the only way to start the Jeep would be to pull the parking lights on and push the brak pedal while starting", then the first relay is redundant. See if this makes any sense:

If you wanted to, you could put a LED on the 87a pin on both relays to show you when the relays are refusing to bypass current. In fact you could rig a harness and make a quick box with 2 LEDs so you could watch the relays open and close to make sure they are working, especially when they stop working, you can see where the current is "stopping"...

The headlight / parking light combo does have a purpose. A would be thief may think of turning the headlights on and would probably hit the brake pedal as a natural reflex, but I'm guessing he would not think to only put the parking lights on......meaning that if the headlights AND parking lights were on, the headlight relay would be open and thus not crank.

You could also put a "short cut" bridge before and after the relay to basically bridge the gap if you had a relay go bad on the road.....just bridge the gap and you could start her right up.

Also, the reliability is an issue and the workmanship would need to be well done to avoid the troublesome bad connections. My thinking is that if you take your time and make sure all connections are good, take your time in placing the relays where they are easily accessable if you know where to look, then this could be an inexpensive way to help secure the Jeep from being stolen.

Fropley made a good point in that you could use any combination of relays to different components to make it even more unique / difficult to start.

Lets keep this thread going just a little longer to see what ideas pop up, I will post the results of my final install when I finish.

The headlight / parking light combo does have a purpose. A would be thief may think of turning the headlights on and would probably hit the brake pedal as a natural reflex, but I'm guessing he would not think to only put the parking lights on......meaning that if the headlights AND parking lights were on, the headlight relay would be open and thus not crank.

Oh ok.... This was the pic I tried to put up when the DB f*cked up earlier this evening:

would it be better to use something just as simple as a single relay, connected to your starter selonoid? the 'switch' to open the relay, and allow current for the relay, to allow current for starting, could be your cigarette lighter. with the ignition off, your lighter shouldnt work anyway. push it in, start er up. any crook to think of usin the cig lighter to start the car?

i'll post up a little diagram of the electrical circuit like geer head did

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Blue Jeep Club member [COLOR=Blue]#100[/COLOR]
1970 DJ-5
3.8 v6
700R4 tranny
countless hours of blood and sweat turning it into a cj-5

you would be using your cig lighter, as the switch to activate the relay, to enable starting. one question, would the cig lighter still work? i mean, it has current going through it, and the switch itself is meant to create resistance, to build up heat in that coil.... would the battery still provide enough amperage to work the relay as well as the lighter? would that put too much amps through the relay itself?

thanks for the input
-mike

__________________
Blue Jeep Club member [COLOR=Blue]#100[/COLOR]
1970 DJ-5
3.8 v6
700R4 tranny
countless hours of blood and sweat turning it into a cj-5

Good question KGB. The beauty of this idea is that you can get as creative as you like with the relays to make it harder for a thief or drunk to start it up

Another thing is to put the radio directly to the battery with an inline fuse and put the relay there, thus making the thief turn the radio on to start it up. Pretty much anything is do-able here, just make sure the workmanship is 1st rate to avoid bad connections.

The downside to all this is exactly what Geerhead mentioned and then solved....put LED's on all the relays and you can easily troubleshoot it.

Another issue is to not make is so %&@$ing complicated that you look like a monkey trying to crank your Jeep. The system needs to be simple enough to look relatively normal, yet complex enough to not be obvious.

I wouldn't count on keeping the cigarette lighter, but if you were willing to give it up, there's no reason you couldn't use it as variable B+ on pin 86. But I'm thinking it would look something more like this:

Also, I've never had much success with working cigarette lighters. They are so buggy and susceptible to corrosion. Just a thought...

As i used to install car alarms this brings me back. All or your viper car alarms all use a simple relay that breaks the starters circuit to not let the car start. Very similer to all of the ideas above.

Its kinda funny though reminds me of the time we put a relay in a co-workers car so that whenever he stepped on his brakes his windshield wipers would turn on.